• Korean Journal of Microbiology
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• v.27 no.2
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• pp.139-146
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• 1989

The mechanisms and metabolic products involved in the degradation of an organophosphate insecticide, diazinon, were studied in submerged paddy soil under the laboratory condition at $30^{\circ}C$. Diazinon abatement in non-sterilized soil was more rapid than indicating microbial participation in diazinon in soil. One-half of the original applications was lost in 2 days and less than 5% remained after 7 days. During the same period, dizinon applications increased tha microbial populations in accordance with the monooxygenase and esterase activities in soil. These results suggest that the microbiological factors develop in soil following diazinon application. The esterase and monooxygenase-catalyzing degradation products of diazinon were isolated and tentatively identified by mass spectrometryas 2-isopropyle-6-methyl-4-hydroxy pyrimidine, diazoxon, hydroxydiazinon, and sulfotep.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.207-212
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• 1983

Isolated Gram-negative bacteria, being capable of degrading toxic, recalcitrant, and pigment-producing furfural, were tentatively identified as Pseudomonas testosteroni, Pseudomonas maltophilia, Klebsiella Pneumoniae, and Pseudomonas fluorescens. They exhibited synergistic effects between P. testosteroni and the others in the degradation of colourproducing furfural. Synergistic effects and possible sequence of its degradation were attempted by manometric technique. P. testosteroni could degrade furfural to decolourize it and produce ninhydrin-reaction postive substance (NPS) which could be utilized by P. maltophilia and K. pneumoniae and the latter two bacteria could ,degrade furfural to 2-furoic acid as an oxidized form. Finally 2-furoic acid was further oxidized by P. fluorescens. Once NPS and 2-furoic acid were produced, the degradation efficiency was enhanced by competing four bacteria against furfural and 2-furoic acid.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.43-46
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• 2006

본 연구는 페라이트의 Fe 양이온 일부를 Ni, Mn, Co등으로 치환하여 M-ferrites를 제조하여 열화학적 2단계 물 분해 반응의 특성을 비교 평가하였고, XRD, SEM, GC등의 분석으로 각 금속산화물의 특성을 확인하였다. M-ferrites는 고상법으로 제조하였다. 각각의 M-ferrites에 대한 열적환원은 1573K에서 진행하였고 물 분해 반응은 1273K에서 실시하였다. 이 반응에서 생성된 가스는 전량 포집하여 GC를 통해 분석하였다. 반응 전후의 시료에 대하여 SEM, XRD를 분석하여 GC결과와 함께 금속산화물의 산화환원반응 특성을 고찰하였다. 그 결과로서 물 분해 반응 후 M-ferrite (M=Co, Ni, Mn)의 생성을 XRD를 통하여 확인할 수 있었고, 물 분해 반응과의 비교결과 격자상수의 증대가 M-ferrite내의 산소의 환원에 영향을 미치는 것을 알 수 있었다. SEM결과에서는 4cycle의 물 분해 반응 후 Mn-ferrite의 심한 sintering 현상을 확인 할 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4597-4603
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• 2010

A factorization is a very important part of multi-level logic synthesis. The number of literals in a factored form is an estimate of the complexity of a logic function, and can be translated directly into the number of transistors required for implementation. Factored forms are described as either algebraic or Boolean, according to the trade-off between run-time and optimization. A Boolean factored form contains fewer number of literals than an algebraic factored form. In this paper, we present a new method for a Boolean factorization. The key idea is to identify two-cube nonkernel Boolean pairs from given expression. Experimental results on various benchmark circuits show the improvements in literal counts over previous other factorization methods.

• Smart Media Journal
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• v.8 no.2
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• pp.74-79
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• 2019

Traditional compound noun decomposition algorithms often face challenges of decomposing compound nouns into separated nouns when unregistered unit noun is included. It is very difficult for those traditional approach to handle such issues because it is impossible to register all existing unit nouns into the dictionary such as proper nouns, coined words, and foreign words in advance. In this paper, in order to solve this problem, compound noun decomposition problem is defined as tag sequence labeling problem and compound noun decomposition method to use syllable unit embedding and deep learning technique is proposed. To recognize unregistered unit nouns without constructing unit noun dictionary, compound nouns are decomposed into unit nouns by using LSTM and linear-chain CRF expressing each syllable that constitutes a compound noun in the continuous vector space.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.3-15
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• 2001

The ozone kinetics including ozone auto-decomposition. effect of pH, and solubility were investigated. Diesel decomposition process including TCE & PCE decomposition. effect of hydroxyl radical scavenger, effect of pH, and ozone/$H_2O$$_2$by ozonation process were also examined using deionized water, simulated groundwater. and actual groundwater. Reactions with deionized water and groundwater both stowed the second-order reaction rates, and the reaction rate was much higher in groundwater (half-life of 14.7 min) than in deionized water (hal(half-life of 37.5 min). The reaction rate was accelerated at high pH values in both waters. The use of ozone showed high oxidation rates of TCE. PCE and diesel. Though hydroxyl radical scavengers existing in groundwater were inhibitors for treating diesel, high pH condition and addition of hydrogen peroxide could accelerate to degrade diesel in groundwater, indicating ozone oxidation process could be applied to treating diesel contaminated-groundwater.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.1-8
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• 1990

The effects of soil environmental conditions on the degradation rates of fenitrothion(O-O-dimethyl O-4-nitro-m-tolyl phosphorothioate) in soils under flooded conditions were examined in the laboratory. Fenitrothion was degraded rapidly and the half life period was within 4 days. Furthermore the degradation was mere rapid under flooded conditions than under upland conditions. The decomposition rate was varied with soils and soil temperatures. Fenitrothion degraded more slowly at 30ppm than at l0ppm. Repeated applications of fenitrothion in soils accelerated the degradation rates. The degradation remarkably increased with amendment of rice straw. However, degradation rates ,were virtually unaffected by the addition of the mixed-fertilizer, the fungicide IBP and the herbicide butachlor. The population of fenitrothion-degrading microbes, which were counted by MPN method, always corresponded with the degradation rates in the soils.

• Journal of KIISE
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• v.45 no.3
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• pp.280-287
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• 2018

Recently, the use of a recommendation system and tensor data analysis, which has high-dimensional data, is increasing, as they allow us to analyze the tensor and extract potential elements and patterns. However, due to the large size and complexity of the tensor, it needs to be decomposed in order to analyze the tensor data. While several tools are used for tensor decomposition such as rTensor, pyTensor, and MATLAB, since such tools run on a single machine, they are unable to handle large data. Also, while distributed tensor decomposition tools based on Hadoop can handle a scalable tensor, its computing speed is too slow. In this paper, we propose S-PARAFAC, which is a tensor decomposition tool based on Apache Spark, in distributed in-memory environments. We converted the PARAFAC algorithm into an Apache Spark version that enables rapid processing of tensor data. We also compared the performance of the Hadoop based tensor tool and S-PARAFAC. The result showed that S-PARAFAC is approximately 4~25 times faster than the Hadoop based tensor tool.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.303-310
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• 1991

Seasonal patterns of decomposition and nutrient release from the needle litter were examined using litter-bags in coastal Pinus thunbergii forests in nothern Kyushu, Japan. Dry matter losses from decomposing needle litter were smillar in all standsover a experimental period. Mass loss in dry weight is lost rapidly during the first year, and thereafter the rate of loss slows. Litter lost approximately 40% of initial mass in 1 yr. The predicted decay constant, k values ranged from 0.5 to 0.6 Decomposition half-times($t_{0.50}$) ranged from 1.1 to 1.4 year. In the decomposing needle litter, the concentrations of N and P generally increased with time while the concentration of K decreased. A decrease in absolute amount was noted for K during decomposition while in an increase was found for N. The order of mobility of elements was K>P>N. Mineralization phase of N had not appeared during the experiment.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.53-60
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• 1999

The biodegradation of recalcitrant polycyclic aromatic hydrocarbon, pyrene was investigated in microcosm simulating the beach sand and seawater. The natural biodegradation rates of pyrene were between 30-2,200 ng/g(ml)/day in beach sand and seawater when the pyrenc loading rates were 100- 1,000 ppm at 5-$20^{\circ}C$. The effects of the inoculum size, pyrene concentralion, incubation temperature and surfactant addition were investigated in fertilized (Inipol EAP 22) samples. Generally the biodegradation in beach sand was higher than that in seawater. A mixed inoculum (Pseudomonus, Acinetobacter, Moruxella) showed the 3,120 nglglday of biodegradation rate in beach sand with 200 ppm pyrene, which was 7.8 times higher than the natural biodegradation rate. The highest transformation rate, 4,860 ng/g/day was obtained in the bioaugmented beach sand (1,000 ppm pyrene). The glucose and surfactant addition to enhance the removal have negatively influenced on the biodegradation of pyrene. In case ol surfactants, CMC (critical micell concentration) might bc the control factor for the biodegradation.